Thought I would throw in my 2 cents, both as a frequent flier in premium cabins and also a viewer of most YouTube vloggers (Josh Cahill, Noel Phillips, Jeb Brooks, Sam Chui, Dennis Bunnik, etc.)
OMAAT is absolutely right, QR couldn't have handled this any worse or any more idiotically. And if they really did fire the crew, shame on them. Anyone can have a bad day, they deserve to receive coaching and feedback and proper training and the opportunity to improve.
I'm just an armchair PR crisis management professional, but here are some suggestions for QR on how to handle this:
1.) You don't want the video removed. You want to keep it up and send the link to all of your management and employees and make them watch it. It's feedback from a customer with a big audience.
2.) Reach out to him, not to silence him, but get his feedback on how they can improve. Ask for a second chance.
3.) Dennis Bunnik had a great video where he got a tour of Qatar Airways' operation behind the scenes. They could do something like that for Cahill. They could showcase their efforts to improve on his experience. They could have him interview the relevant VP in charge of customer experience.
Any airline, in any situation, at any time can provide a negative or disappointing experience. It's how they implement the feedback and improve that counts. QR is going to learn that if they are going to grow in the rest of the world and do business with the Western world, they are going to get used to accepting criticism.